Several billion pennies with 'wheat backs' were made between 1909 and 1958. Having a wheat back is not what makes a Lincoln cent valuable. Very low mintage for a date/mint, or extremely high condition grade for some common dates, are what make coins valuable.
Your 1945, in that worn condition, is worth two cents in copper. If it was mixed with other 'wheat' cents and you had a couple hundred of them, a dealer might give you three or four cents each on the chance that they find a better date in the pile. Between the three mints that made them in 1945, nearly 2.5 billion Lincoln cents were made.